© ⅯⅯⅩⅢ Kirby Morgan Dive Systems, Inc. All rights reserved. Document # 130115001
41
SuperLite
®
27
®
for a short time outside the trunk until he is sure all
systems are operating properly.
During the decent the communications must be
checked again and the diver supply pressure should
be adjusted as necessary to maintain the required
over-bottom pressure. It may be necessary for the
diver to readjust the demand regulator by means of
the adjustment knob once at the work site to compen
-
sate for any variation in umbilical supply pressure.
3.9.8 adjust Regulator for Low Work Rates
At very low work rates, such as when the diver is
resting, or during in-water decompression, the diver’s
respiratory rate may be quite slow (10-15 breaths per
minute). When this occurs, the diver’s exhalations
may not be sufficient to move enough breathing gas
through the helmet exhaust to adequately wash out
carbon dioxide (CO
2
).
In order to ensure that carbon dioxide does not ac
-
cumulate in the helmet, divers who are at rest under
-
water should screw the regulator adjustment knob
“out,” i.e., away from the regulator, until a slight
steady flow occurs and the regulator can be heard to
hiss. This will help to eliminate any excess carbon
dioxide from the helmet. An alternate to this would
be to open the steady flow (defog valve) just slightly.
WARNING
Excess carbon dioxide (CO2) is danger-
ous. Too much carbon dioxide in the div-
er’s breathing system can cause the diver
to feel that he cannot breathe for comfort.
In extreme circumstances, carbon dioxide
can cause unconsciousness. This could
lead to suffocation and death.
